To combine pictures into one file, you arrange 2 to 12 local images on a single canvas with a chosen layout, gap, and background color, then export the stitched result as one PNG. The Combine Images tool performs this task entirely in your browser using PNG, JPEG, WebP, GIF, AVIF, or BMP as input — and writes the result as a single PNG. Because decoding, layout math, drawing, PNG encoding, and the download Blob all happen in the active tab, the source files never travel to a server. The tool also accepts a gap from 0 to 100 pixels and a six-digit background color, so you can control the look of empty canvas space and the strips between images. Readers who searched specifically for a PDF should know upfront that this workflow outputs a PNG, not a multi-page PDF; for true PDF output with one image per page, the Image to PDF tool is the matching option. The rest of this article explains the steps, layouts, and limits in enough detail to plan your combine before you click anything.
What it actually means to combine pictures into one file
The phrase covers two related but technically different tasks. The first is "stitch" — lay pictures next to each other on a single canvas and export the whole thing as one image. The second is "package" — bundle several full-resolution pictures inside a multi-page document such as a PDF, where each picture keeps its own page and dimensions. A quick mental test clarifies which task you actually have. If your end goal is to share one viewable image in a chat, post, or social upload, stitching into one PNG is usually faster and lighter. If your end goal is to submit a printable packet, an official archive, or a multi-page report, packaging into a PDF is the better match because each page renders independently at its native size.
Search engines often return both kinds of results for the same query, which is why a "combine pictures into one PDF" search can land on a stitching tool. The tool covered here is a stitcher. The stitched output behaves like one larger picture: opening it shows every input side by side, top to bottom, or on a grid, and the file size is similar to a single photo of the same canvas. That is enough for most sharing, viewing, and lightweight archiving needs, and it sidesteps any PDF reader dependency for the recipient. If the recipient needs to flip pages or print on standard paper, the artifact has to be a PDF instead.
When a single PNG is enough and when PDF is the right choice
A single PNG combine is the right pick when the recipient needs to see everything at once and does not need to flip between separate pages. Common fits include a contact sheet of three product photos for a marketplace listing, a before-and-after pair for a portfolio post, a row of four screenshots stitched for a bug report, or a grid of screenshots turned into one tall image for a how-to document. Each of these works as one continuous image, the original aspect ratios of every picture are preserved, and the file opens on every phone and computer without a PDF reader.
A multi-page PDF is the right pick when the recipient needs each picture at its own size on its own page, when the file will be printed on standard paper, when an upload portal expects PDF, or when the final artifact is going into a system that indexes per-page text and metadata. For those cases, the Image to PDF tool handles the same input set but produces one PDF with each picture on a separate page at its decoded pixel dimensions. Many readers end up using both tools together — Combine Images to make a single overview PNG, Image to PDF to make a printable PDF — because the two outputs serve different audiences and serve them better than one artifact stretched across both jobs.
Combine pictures into one file in your browser
The workflow below is the exact path the Combine Images tool runs through your browser tab. No step requires an account, an upload, or an installation.
- Open the Combine Images tool in your browser. Keep the tab focused while the tool decodes each picture so memory can be reclaimed promptly after the canvas is encoded.
- Choose between two and twelve supported raster files in the order you want them placed. The browser preserves this order all the way through to the canvas, so renaming files to numeric prefixes (01, 02, 03) before selecting them is the simplest way to control sequence.
- Pick a layout: horizontal, vertical, or grid. Horizontal lays images from left to right, vertical stacks them top to bottom, and grid packs them into a square-like grid whose column count is the ceiling of the square root of the image count.
- Set the gap between 0 and 100 pixels. The gap is added between every adjacent pair of pictures and is also visible as the chosen background color on every empty cell and unused area.
- Set the background color with the six-digit color picker. Pick a hex value such as #FFFFFF for white, #000000 for black, or a brand color. The color is painted as the first canvas operation, so it will show through any transparent pixels in your source files.
- Choose Combine images. The tool decodes each file with the browser's bitmap path, computes the canvas, draws each picture once at its decoded pixel size, and encodes the result with the browser's built-in PNG encoder.
- Verify the output dimensions displayed beneath the result and download the generated PNG. The download uses a revocable object URL so memory can be released as soon as the file is saved to disk.
Choosing between horizontal, vertical, and grid layouts
The three layouts are not just visual styles — each one follows a fixed formula for canvas dimensions, so you can predict the size of the output before you click combine. The table below summarizes the verified rules.
| Layout | Output width | Output height | Centering rule | Best fit |
|---|---|---|---|---|
| Horizontal | Sum of all widths plus the gap between every adjacent pair | Tallest image height in the set | Shorter pictures are centered vertically inside the row | Side-by-side comparisons, before-and-after pairs, contact sheets viewed on a wide screen |
| Vertical | Widest image width in the set | Sum of all heights plus the gap between every adjacent pair | Narrower pictures are centered horizontally inside the column | Tall scrolling posts, step-by-step screenshot sequences, story-style photo threads |
| Grid | Column count times the widest image, plus gaps between columns | Row count times the tallest image, plus gaps between rows | Each picture is centered inside its cell without stretching or cropping | Equal-weight collections such as product variants, color options, or app screens |
A worked example with three pictures makes the math concrete. Suppose you select files at 800×600, 1200×900, and 600×400 with a 20-pixel gap, and choose horizontal layout. Output width = 800 + 20 + 1200 + 20 + 600 = 2640 pixels. Output height = 900 pixels, which is the tallest of the three. The 800×600 picture is centered vertically inside the 900-pixel canvas, leaving 150 pixels of chosen background above and below it; the 600×400 picture is centered the same way and leaves 250 pixels above and below. The 1200×900 picture is drawn at its full height and fills the canvas top to bottom.
For grid layout, take the ceiling of the square root of the image count. With 8 pictures, the square root of 8 is about 2.83, so the column count is 3 and the row count is the ceiling of 8 divided by 3, which is 3 rows. The last row therefore contains only 2 pictures, and the remaining cell shows the chosen background color. Every cell is sized to the widest decoded image as its width and the tallest decoded image as its height, and each source picture is centered inside that cell without any scaling or cropping.
Inputs, formats, and size limits the tool accepts
The tool works against the formats your browser can decode through its standard image bitmap path. Anything else is rejected up front so the workflow stays bounded and predictable.
| Format | Accepted | Notes |
|---|---|---|
| PNG | Yes | Decoded at full resolution; transparency is preserved through decode but becomes the background color in the final PNG. |
| JPEG | Yes | Common for photos; no EXIF, color profile, or orientation tag is preserved in the output. |
| WebP | Yes | Still frames decode fine; only the first decoded frame of an animated WebP is used. |
| GIF | Yes | Still frames decode fine; only the first decoded frame of an animated GIF is used. |
| AVIF | Yes | Still frames decode fine; only the first decoded frame of an animated AVIF is used. |
| BMP | Yes | Decoded at full resolution; treated as opaque by default unless the file carries an alpha channel. |
| SVG | No | Rejected by design — SVG can reference external resources or contain very large render instructions, so it is excluded from this local raster workflow. |
Three hard limits apply before the tool will run a combine. Each source file must be 25 MiB or smaller. The sum of every selected file must be 100 MiB or smaller. The resulting canvas must be 8192 pixels or smaller on each side and must not exceed 32 million pixels in total area. These caps exist because browser tabs can crash when image bitmaps consume too much memory, and the tool prefers to refuse a combine it cannot safely finish rather than freeze the tab.
Files whose extension looks familiar may still fail when their bytes are corrupt or their codec is unsupported by the current browser. If a file is rejected, the most common causes are an SVG mistakenly renamed to PNG, a corrupted download, or a format such as HEIC that some browsers do not yet decode natively. Re-encoding the file in a known-good raster format usually fixes the rejection.
Transparency, animation, and metadata in the combined PNG
Three properties of the inputs behave differently in the output, and these behaviors are intentional rather than bugs. Understanding them up front prevents surprises after a combine finishes.
Transparency becomes background. The selected opaque background color is painted on the canvas first, then every picture is drawn on top. Any transparent area in a source file shows the chosen background color in the exported PNG. If you want the original transparency preserved, pick a color you do not mind showing through, because the tool always outputs PNG and always paints an opaque background before the images, leaving an opaque file unless a picture fills every pixel on its own.
Animation is dropped. Animated GIF, animated WebP, and animated AVIF inputs each contribute the single frame decoded by the browser's bitmap path. The output is one static PNG with no timeline, no frame timing, and no looping. If your goal is to keep the animation across several images, the GIF Maker tool builds an animated GIF from a set of still frames entirely in your browser.
Metadata is dropped. The tool does not preserve EXIF, color profiles, layer information, or original filenames in the output PNG. The exported file contains only the decoded pixels, encoded once by the browser's PNG encoder, with no added metadata and no compression toward a target byte size. For print production or color-managed compositing, open the exported PNG in dedicated software and re-attach the color profile you need before sending the file to a press.
When a multi-page PDF is actually what you need
If your real goal is one image per page inside a printable document, a stitched PNG is the wrong artifact. Pick a true PDF output instead. The Image to PDF tool accepts the same set of raster inputs and produces one PDF with each picture on its own page at its decoded pixel size, which keeps every image sharp and avoids any resampling. Use it for tax document submissions, contract bundles, scanned receipts, school paperwork, and any portal that explicitly requires PDF.
For readers who only need a quick visual overview — a contact sheet to share, a side-by-side comparison for a chat, or a grid of product photos for a marketplace listing — the stitched PNG is faster, smaller, and easier to view on any device. Pick the layout that matches your screen shape, set a gap and a background color that fit your brand, and the combine runs locally in your tab. The math behind the canvas dimensions is straightforward enough that you can plan the output size on paper before you open the file picker, and the verified limits on file size and canvas dimensions let you know up front whether the tool can finish the job.
If you're weighing options, EXIF Remover Alternative: Strip Metadata Without Uploading covers this in detail.